Oxidative dehydrogenation, particularly oxidative dehydrogenation of n-butenes to make 1,3 butadiene is known. Process details are discussed at some length in Welch et al., Butadiene via oxidative dehydrogenation, Hydrocarbon Processing, November 1978, pp. 131-136. A high ratio of superheated steam to hydrocarbon in the feed supplies the necessary heat and increases the per pass yields by reducing partial pressures. Steam also acts as a heat sink in an adiabatic reaction system to moderate temperature rise during the intensely exothermic reaction. U.S. Pat. No. 7,034,195, to Schindler et al., discusses a two stage oxydehydrogenation arrangement at Col. 10, lines 38-53, but does not address the temperature control. U.S. Pat. No. 8,088,962, to Klanner et al., mentions multi-zone reactors at Col. 17, lines 51-56 in connection with 2-zone multiple catalyst tube fixed bed reactors. See, also, U.S. Pat. No. 6,998,504, to Unverricht et al. which recites tube-bundle reactors.
U.S. Pat. No. 3,925,498 to Stadig discloses an oxidative dehydrogenation process wherein steam and oxygen are added in stages through spargers to increase oxygen levels and conversion of raw material.
Fixed bed, adiabatic reactors are preferred over tube-bundle reactors because of their simple construction, low capital costs and low operating and maintenance costs as well as well established operational know-how with these reactors. In a traditional version of the oxidative dehydrogenation process, a large flow of steam is used to control the exotherm.